(U. S. P.). A dressing for wounds made by dissolving guncotton in ether; it is used as a substitute for adhesive plaster. See Pyroxylin. C, Acetone, one prepared from guncotton, 5 parts; ether, 10 parts; alcohol, 10 parts; acetone, 20 parts; castor-oil, 6 parts. It is more elastic than ordinary flexible collodion. C, Cantharidal (collodium can- tharidatum, U. S. P.), a blistering solution of collodion and cantharides. C, Flexible (collodium flexile, U. S. P.), collodion with the addition of castor-oil and Canada balsam. C, Iodized, flexible collodion with the addi- tion of 5 % of iodin. It is used in chilblains. C, Iodoform, flexible collodion with 5 % of iodoform. C, Styptic (collodium stypticum, U. S. P.), a mixture of collodion with tannic acid, ether, and alcohol.